Combustion apparatus for gas turbine

ABSTRACT

A gas turbine having a combustion chamber with a fuel nozzle is encompassed by a plurality of annular plenum chambers which are supplied with a pressurized fluid. The fluid is directed obliquely through ports toward a fuel stream being sprayed into the combustion chamber. The angle at which the fluid is directed aids in the formation of a vortex. The fluid also adds to the turbulence within the fuel vortex to reduce the carbon pollutant outflow.

United States Patent 1 1 [111 3,886,736 Kawaguchi June 3, 1975 l lCOMBUSTlON APPARATUS FOR GAS 3.684.186 8/1972 Helmrich 239/400 3.700,l7310/1972 Kctchum.... 239/405 1 3.731169 5/1973 Lefebvrew 239/405 X [75]Inventor: Katsuyuki Kawaguchi. Akzishi. 3,735.930 5/1973 Mori 239/406 XJapan 3.777.983 12/1973 l-libbins 60/3974 B [73] Assignee: WestinghouseElectric Corporation.

Pittsburgh. Pa. Primary Eraminer-C. J. Husar Ass-[slant Examiner-RobertE. Garrett [22 Filed 1973 Attorney. Agent, or FirmG. H. Telfer [21]Appl. No: 411,497

[57] ABSTRACT [30] Foreign Applicatlon Priority Data Nov. 9. m2 Japan47-l1l6l9 A gas turbine having a Combustion Chamber with fuel nozzle isencompassed by a plurality of annular 52 us. Cl 60/3974 R; 239/400;239/402; P m Chambers which are pp ith a pr 239/4O6 1zed fluid. Thefluid is directed obliquely through ports 51 Int. Cl. 3051) 7/10; FOZc3/00 f a fuel Stream being p y into the combus- 5 n w f Search 60/3974 R3974 13; tion chamber. The angle at which the fluid is directed 239/400,403-406, 4245 ands 1n the formation of a vortex. The fluid also adds tothe turbulence within the fuel vortex to reduce the [56] ReferencesCited carbon pollutant outflow.

LNITED STATES PATENTS 4 Claims, 3 Drawing Figures 3.498 055 3/1970Fuituni et ul. 60/3974 R 1 COMBUSTION APPARATUS FOR GAS TURBINE CROSSREFERENCES TO RELATED APPLICATIONS This invention is based on anapplication filed by the same inventor in Japan. The Japaneseapplication number and its filing date is as follows:

111619/72 filed Nov. 9, 1972.

BACKGROUND OF THE INVENTION l. Field of the Invention:

This invention relates to combustion apparatus for a gas turbine, andmore particularly to means for mixing fluid streams with the fuel toatomize. disperse or convolute the fuel to provide complete combustionthereof.

2. Prior Art:

Early arrangements of baffling and mixing of atomizing fluids and fuelshave generally been concerned with increasing the thermal combustionefficiency and optimizing the temperature distribution of the productsof combustion to eliminate hot spots and prevent burnout of thecomponents in the flow path of the products of the combustion. However,with the increased interest in ecology, interest has been generated inproviding a thorough mixing of the fuel and an abatement of theproduction of smoke and obnoxious nitrogen-oxygen compounds produced bythe combustion of fuel in the gas turbine. An earlier application filedin the name of this inventor showing some prior art is US. Pat. No.3,768,250.

SUMMARY OF THE INVENTION In general, a combustion apparatus for a gasturbine, when made in accordance with this invention, cornprises a fuelsupply conduit having a pore in fluid communication with a combustionchamber to direct the flow of fuel to the combustion chamber, anatomizing fluid chamber having an opening disposed to direct atomizingfluid to converge with the fluid flowing into the combustion chamber, anannular chamber disposed to encircle the fuel supply conduit having oneend thereof in communication with the combustion chamber, the other endbeing in communication with the compressor portion of the gas turbine,the annular chamber having a plurality of angularly directed vanes sodisposed therein to cause air flowing therethrough to follow avortecular path as it leaves the exit end of the annular chamber andenters the combustion chamber, and generally radially inwardly disposedand generally radially outwardly disposed angularly directed annulararray of ports, through which air is passed, which aid the vortecularmotion and inner turbulence of the fuel-air mixture in the combustionchamber. Each of the annular arrays of ports and the vanes direct theirrespective air flows generally parallel to one another, while alsocontributing to the generally overall convolute flow pattern.

BRIEF DESCRIPTION OF THE DRAWING];

I he objects and advantages of the invention will be come more apparentfrom reading the following detailed description in connection with theaccompany ng FIG. 2 is a view taken along lines ll-ll of FIG. 1; and,

FIG. 3 is a view taken along lines Illlll of FIG. 2.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to thedrawings in detail, and more particularly to FIG. 1, wherein there isshown a combustion apparatus 10 for a gas turbine, not shown, having acombustion chamber 12, a compressor 13, to supply pressurized air forcombustion, and a supply conduit 14 to supply atomizing fluid to atomizethe fuel.

A fuel supply conduit 16 delivers fuel to a fuel supply nozzle 18 whichhas at least one pore or opening 19 from which fuel is sprayed into thecombustion chamber 12. An outer plenum chamber 20 encircles thecombustion apparatus 10 and it is in communication with an air sourcethrough a plurality of ports 22 disposed in a cylindrical outer wall 24of the plenum chamber 20. A plurality of angularly directed vanes 26 arefastened to and extend generally radially outward from an innercylindrical wall 28 of the plenum chamber 20. The angularly directedvanes 26 are adapted to cause the air flowing through the plenum chamber20 to follow a convolute path, directed at an angle of 30 to to axis ofthe combustion chamber 12, as it enters that combustion chamber. Afrustoconical baffle 30 has its small diameter end fastened to the innerwall 28 of the plenum chamber 20 and has a plurality of annularlydisposed ports of jets 32 angularly directed to 30 to 35 from the axisof the combustion chamber 12. The vanes 26 and the ports 32 both directtheir respective air flows generally parallel to one another. Each airflow adds to and combines with the vortecular motion of the atomizingfuel spray. The jets 32 may also direct their air flows normal to thefuel-air vortex to increase the turbulence and fuel-air mixing therein.

An inner plenum chamber 34 is provided adjacent the fuel nozzle 18 andis supplied with atomizing fluid through the atomizing conduit 14. Theatomizing fluid flows through an annular opening 36 adjacent the tip ofthe nozzle 18 and is directed at an angle toward the fuel convergingwith the fuel flowing into the combustion chamber.

An intermediate plenum chamber 38 is formed between the inner and outerannular chambers, 34 and 20, respectively, and a plurality of ports 40are disposed in the inner wall 28 of the outer plenum chamber 20. Theintermediate annular plenum chamber 38 is in fluid communication withthe combustion chamber 12 by a plurality of angularly disposed ports orjets 42, which may be directed at at angle of 30 to with respect to theaxis of the combustion chamber. the air flow therethrough beinggenerally parallel to that vortecular air flow pattern caused by thevanes 26 and the outer array of ports 32.

The array of vanes 26 and the angular arrays of inner and outer ports,42, and 32, are shown in FIG. 2.

The angularity of the vanes 26 and the outer ports 32 are shown in FIG,3. The object of this invention is to provide a combustion apparatus inwhich the carbon that is produced in an initial combustion zone isdecreased by supplying vortex air in three steps so as widen the angleof the fuel injection cone, thereby making the fuel particle sizesmaller, effectively improving the ignitability of the fuel and finallyshortening the length of the flame. The atomization of the fuel isincreased by the application ofa swirl flow having the same vortexdirection as that of the fuel injection cone. Additionally. the jettedair penetrates the fuel injection cone to provide internal turbulenceand mixing thereof. As the combustion pressure increases duringcombustion operation, a pressure balance piston 44 admits additional airfrom the combustion air source. which may be a compressor, as shown inFIG. I, the air being passed through an annular chamber 46 disposedabout the fuel supply conduit, to mix with the air in the intermediateannular chamber 38 prior to injection into the combustion chamber 12.The air from the outer annular array of ports 32 passes into the fuelinjection Cone without contracting the injection cone because the airflow has its own vortecular components, and the conical angle of thevortex is increased by the air flow from the inner annular array ofports 42. The mixing of fresh air with the circulating combustible fuelgas flow can be achieved quickly, and the combustion load factor can beincreased to the state in which a stable combustion zone and fuel airratio is effectively and highly maintained. Thus the mixture of air andfuel is sufficiently promoted and the carbon output due to incompletecombustion is reduced.

I claim:

1. A combustion apparatus for a gas turbine having a combustion chamber,a fuel supply. a compressor to supply a pressurized air for combustion,a supply of pressurized atomizing fluid to atomize the fuel, saidcombustion apparatus comprising:

a fuel supply nozzle having at least one port in com munication withsaid combustion chamber and disposed to direct the flow of fuel to saidcombustion chamber;

an atomizing fluid chamber having walls which define at least one ductdisposed to direct atomizing fluid into said combustion chamber so thatit converges with fuel flowing thereto;

a plenum chamber comprised of walls disposed about said atomizing fluidchamber;

a first array of angularly arranged ports disposed through said wall ofsaid plenum chamber and disposed about said fuel nozzle, said firstarray of angularly arranged ports providing jets of air to promotevortecular motion to the fuel in said combustion chamber;

a frustoconical baffle having its small diameter edge attached to saidwalls of said plenum chamber, said baffle being annularly disposed aboutsaid nozzle; a second array of angularly arranged ports disposed throughsaid baffle about said fuel nozzle, said second array of angularlyarranged ports providing jets of air to promote mixing and increasevortecular motion of the combustion components; an arcuate chamberdisposed radially outwardly of said plenum chamber. said arcuate chamberhaving walls with inlet ports therethrough, said arcuate chamber beingin communication with said compressor and said combustion chamber, and agenerally radially extending array of vanes disposed across said arcuatechamber for causing the air passing therethrough to have a vortecularmotion as it enters the combustion chamber; said first and second arraysof ports and said array of vanes each directing generally the same angleto the fluid passing thereby, with respect to the axis of the combustionchamber;

said array of vanes and said first and Second arrays of ports beingarranged as to cause the air and fuel to follow a vortecular motion, andto increase the turbulence therein, thereby reducing the smoke generatedtherewith.

2. combustion apparatus as recited in claim 1, wh erein said first arrayof ports have an angle betwee 3Q to 45 with the axis of the combustionchamber, said second array of ports having an angle of 30 to 35 with theaxis of the combustion chamber, and said array of vanes having an angleof between 30 to 35 with the axis of the combustion chamber.

combustion apparatus as recited in claim 1, wherein said first array ofports is disposed in an angular array about the downstream end of thefuel nozzle, and said second array of ports are disposed radiallyoutwardly of the said first array of ports.

combustion apparatus as recited in claim 1, wherein said second array ofports is directed generally normal to the fuel vortex, the air passingthrough said second array of ports promoting turbulence and mixing ofthe'fuel and air within the center of said vortex, thereby reducingcarbon and smoke production from the combustion chamber.

1. A combustion apparatus for a gas turbine having a combustion chamber,a fuel supply, a compressor to supply a pressurized air for combustion,a supply of pressurized atomizing fluid to atomize the fuel, saidcombustion apparatus comprising: a fuel supply nozzle having at leastone port in communication with said combustion chamber and disposed todirect the flow of fuel to said combustion chamber; an atomizing fluidchamber having walls which define at least one duct disposed to directatomizing fluid into said combustion chamber so that it converges withfuel flowing thereto; a plenum chamber comprised of walls disposed aboutsaid atomizing fluid chamber; a first array of angularly arranged portsdisposed through said wall of said plenum chamber and disposed aboutsaid fuel nozzle, said first array of angularly arranged ports providingjets of air to promote vortecular motion to the fuel in said combustionchamber; a frustoconical baffle having its small diameter edge attachedto said walls of said plenum chamber, said baffle being annularlydisposed about said nozzle; a second array of angularly arranged portsdisposed through said baffle about said fuel nozzle, said second arrayof angularly arranged ports providing jets of air to promote mixing andincrease vortecular motion of the combustion components; an arcuatechamber disposed radially outwardly of said plenum chamber, said arcuatechamber having walls with inlet ports therethrough, said arcuate chamberbeing in communication with said compressor and said combustion chamber,and a generally radially extending array of vanes disposed across saidarcuate chamber for causing the air passing therethrough to have avortecular motion as it enters the combustion chamber; said first andsecond arrays of ports and said array of vanes each directing generallythe same angle to the fluid passing thereby, with respect to the axis ofthe combustion chamber; said array of vanes and said first and secondarrays of ports being arranged as to cause the air and fuel to follow avortecular motion, and to increase the turbulence therein, therebyreducing the smoke generated therewith.
 1. A combustion apparatus for agas turbine having a combustion chamber, a fuel supply, a compressor tosupply a pressurized air for combustion, a supply of pressurizedatomizing fluid to atomize the fuel, said combustion apparatuscomprising: a fuel supply nozzle having at least one port incommunication with said combustion chamber and disposed to direct theflow of fuel to said combustion chamber; an atomizing fluid chamberhaving walls which define at least one duct disposed to direct atomizingfluid into said combustion chamber so that it converges with fuelflowing thereto; a plenum chamber comprised of walls disposed about saidatomizing fluid chamber; a first array of angularly arranged portsdisposed through said wall of said plenum chamber and disposed aboutsaid fuel nozzle, said first array of angularly arranged ports providingjets of air to promote vortecular motion to the fuel in said combustionchamber; a frustoconical baffle having its small diameter edge attachedto said walls of said plenum chamber, said baffle being annularlydisposed about said nozzle; a second array of angularly arranged portsdisposed through said baffle about said fuel nozzle, said second arrayof angularly arranged ports providing jets of air to promote mixing andincrease vortecular motion of the combustion components; an arcuatechamber disposed radially outwardly of said plenum chamber, said arcuatechamber having walls with inlet ports therethrough, said arcuate chamberbeing in communication with said compressor and said combustion chamber,and a generally radially extending array of vanes disposed across saidarcuate chamber for causing the air passing therethrough to have avortecular motion as it enters the combustion chamber; said first andsecond arrays of ports and said array of vanes each directing generallythe same angle to the fluid passing thereby, with respect to the axis ofthe combustion chamber; said array of vanes and said first and secondarrays of ports being arranged as to cause the air and fuel to follow avortecular motion, and to increase the turbulence therein, therebyreducing the smoke generated therewith.
 2. A combustion apparatus asrecited in claim 1, wherein said first array of ports have an anglebetwee 30* to 45* with the axis of the combustion chamber, said secondarray of ports having an angle of 30* to 35* with the axis of thecombustion chamber, and said array of vanes having an angle of between30* to 35* with the axis of the combustion chamber.
 3. A combustionapparatus as recited in claim 1, wherein said first array of ports isdisposed in an angular array about the downstream end of the fuelnozzle, and said second array of ports are disposed radially outwardlyof the said first array of ports.